1. Field of the Invention
The present invention relates to a sanding tool, and more particularly to a sanding tool for making a surface to be repaired into a flat surface.
2. Prior Art
A procedure for repairing flaws and dents on a painted surface in a vehicle such as an automobile is as follows. As shown in FIG. 10, a primer 51, a surfacer 52, and paint 53 which have been applied on a steel sheet 50 are first removed, and then, a dent is filled with a putty 1 or the like in an amount somewhat larger than a volume of the dent.
Thereafter, a surface (a part damaged) filled with the putty 1 or the like is sanded to make the same flush with a surface of the vehicle body as shown in FIG. 11. This step for the procedure is sanding the surface filled with a putty so as to flatten the same by the use of sandpapers belonging to several degrees extending over coarse grains to fine grains. In this respect, it is no exaggeration to say that a result of final repair is decided by a skill relating to this step.
A tool used for the sanding treatment has a structure wherein a sandpaper is exchangeably stretched on a base plate 54 having a rectangular flat surface as shown in FIG. 11. The base plate 54 is provided with a grip 55 on the top thereof, and sanding operation is carried out by an operator while holding the grip 55 with an operator""s hand (or hands) in reciprocating or circular motion or the like.
Although it seems a reasonable conclusion that since the base plate 54 has a flat surface, an irregular putty surface can be sanded into a flat surface. In reality, however, when such a putty surface is sanded, a flat surface cannot be necessarily realized. This is because the base plate 54 is held by a human hand so that the base plate 54 performs a kind of a wooden pestle motion, and it results in a very slight irregular surface. Moreover, such tendency increases because a sanding operation is principally carried out with a peripheral part of the base plate 54.
In this connection, for eliminating such disadvantage, it is considered that an irregular surface, particularly a convex surface in a putty-filled surface is sanded with the use of an edge portion of the base plate 54 (by inclinedly holding the base plate 54) to smoothen the irregular surface.
However, since the edge portion of the base plate 54 is not a plane, but a linear configuration, as a matter of course, an area of the edge portion being in contact with the putty surface is extremely small. Accordingly, even when an operator intends to execute such a suitable operation while maintaining a sanding tool at a pertinent angle in order to obtain a smooth sanded surface, there is insufficient stability, so that high skill is required to achieve good operation.
Besides, there is also such a problem of easily wearing off sandpaper occupying the edge portion thereof.
An object of the present invention is to provide a sanding tool with which a surface to be repaired can be sanded into a flat surface by a comparatively easy operation.
Another object of the invention is to provide a sanding tool with which a surface to be repaired can be sanded into a flat surface for a short period of time, and in addition, stable feeling in operation therefor can be provided.
Still another object of the invention is to provide a sanding tool in which local excessive wear of sandpaper is prevented.
A further object of the invention is to provide a sanding tool having good operability at a low cost.
The subject matter of the invention resides in a sanding tool for sanding a surface of apart to be repaired into a prescribed condition, characterized in that it is provided with a base plate on the front surface side on which can be stretched sandpaper, and a movable base plate which is disposed bendably at the end of the base plate and on the front face side of which can be stretched sandpaper; and the movable base plate is energized resiliently in a direction wherein the surfaces of the movable plate become flush with the surface of the base plate.
A movable range of the movable base plate may be arranged to be bent at an angle which has been previously established within a range extending from the same plane with that of the base plate (zero degrees) to an angle of 10 degrees with respect to the base plate.
Moreover, a resilient means may be disposed between the base plate and the movable base plate.
As the resilient means described above, a coil spring or the like is suitable, and it may arranged to specify a positional relationship between the movable base plate and the base plate, whereby the movable base plate becomes flush with the base plate, in the case when no external force is applied to these plates.
A preferred contour of the base plate is rectangular, and the longer side of the base plate is preferably hinged to the movable base plate. Moreover, movable base plates are preferably hinged to opposite sides (both the longer sides) of the base plate, respectively. In addition, it is preferred that the movable base plate is formed into a smaller size than that of the base plate.
Furthermore, a grip may be attached to the top of the base plate such that an operator can execute an operation of the sanding tool by holding the same with his (or her) hand(s). Further, it is also possible to apply the sanding tool to an electrically-driven device or the like which will produce vibrations or will suck dust through an attachment.
According to the present invention, a sanding tool thereof is constituted such that movable base plates are disposed on the opposite ends of a base plate, and when a movable base plate side is pressed, it is bent upwardly with respect to the base plate (or the base plate is bent upwardly with respect to the movable base plate). Thus, it is possible that an edge portion of the sanding tool is allowed to be in contact with a surface to be repaired as a plane in a condition where the sanding tool is allowed to bend.
For this reason, even if a surface to be repaired has been in a fine irregular surface, such irregular surface can be efficiently sanded, so that the surface to be repaired can be sanded into a flat surface with a comparatively easy operation.
Furthermore, in accordance with the present invention, it becomes possible to provide a sanding tool which brings about a feeling of stable operation, and at the same time, by which a surface to be repaired can be sanded into a flat surface in a short period of time.
Moreover, since sandpaper used in a sanding tool according to the present invention is in contact with a surface to be repaired in a plane, it is possible to prevent local excessive wear of the sandpaper, so that a life of the sandpaper can also be prolonged.
In addition to the above description, it is possible to provide a sanding tool having good operability at a low cost according to the present invention.
The present inventor has found in the case where a surface to be repaired is sanded with a sanding tool that when a sort of dot sanding is continued, it brings about a sort of linear sanding, and further when a sort of linear sanding is continued, it brings about a sort of planar sanding. In other words, when it is intended to perform planar sanding at a blast (sanding over a wide area at a blast), it is difficult to carry out a fine sanding operation. In this respect, when a sanding tool according to the present invention is used, stable linear sanding can easily be continuously carried out, so that an extremely good finish can be realized over the whole surface to be repaired for a short period of time.
In this connection, even if a surface to be repaired is a curved surface, a good sanding operation can be easily effected in accordance with a sanding tool of the present invention.